Dual Sensory Loss (DSL) is the co-occurrence of vision and hearing loss. The prevalence of DSL rises steeply with age and is expected to increase as the American population ages. People with DSL have increased difficulties in daily functioning, because many real-life tasks require both vision and hearing. Despite extensive attention to the rehabilitation for vision and hearing loss separately, very little attention has been paid to the specific challenges faced by people with DSL. The candidate?s long term goal is to improve the quality of life and independence of people with DSL by optimizing the utilization of their residual vision and hearing. The current study focuses on their spatial localization. Spatial localization refers to determining the direction of sounds and visual objects in the environment, and it is important for safe mobility and effective social interaction. In the K99 phase, the candidate?s goal is to investigate the impacts of vision and hearing deficits, both individually and in combination, on the spatial localization of people with DSL, and to establish a spatial ?perimetry? measure to characterize these effects. In a controlled laboratory context (Aim 1), the candidate plans to measure the localization perimetry of subjects with DSL, in each of the visual, auditory, and audiovisual conditions. The candidate will then measure subjects? localization ability in two simulated real-life tasks (Aim 2): understanding a speaker among a group of people, and localizing a car that is about to move in a parking lot. The findings in Aim 1 will be verified in these ecologically relevant social and mobility contexts in Aim 2. In the R00 phase, the candidate?s goal is to develop and evaluate training methods that can improve the spatial localization ability of people with DSL. The candidate proposes that a training plan needs to be tailored based on the evaluation of the individual?s spatial localization ability. Two training methods are developed with the purposes of recalibrating the visual and auditory space perception, improving auditory and visual spatial localization ability, and facilitating audiovisual combination to maximize the use of residual vision and hearing. The K99 phase will take place in the University of Minnesota, where the candidate will be jointly mentored by Dr. Gordon Legge who specializes in low-vision research, Dr. Peggy Nelson who specializes in hearing-loss research, and Dr. Dan Kersten who specializes in computational vision science. The candidate will also receive excellent advice in auditory perception from Dr. Andrew Oxenham, in ophthalmology from Dr. Erik van Kuijk and in audiology from Dr. Evelyn Davies-Venn. The training plan is to extend the candidate?s knowledge in translational vision and hearing science, the techniques of multisensory modelling, the pathology of vision and hearing impairment, and the contemporary strategies of assessment and rehabilitation. With successful training, the candidate will independently conduct the studies in the R00 phase. The candidate?s career goal is to lead a research team to improve the life quality and independence of people with DSL.